Rock-polishing rumble

ABSTRACT

A molded tubular drum of elastomeric material having a generally cylindrical external shape and a polygonal internal shape. Identical and closures for the drum, each also of molded elastomeric material and each having a radial end wall, an axially inwardly extending center plug shaped to snugly fit within the inner cavity of the drum, and a peripheral drive rim. A girth rib and girth groove seal is provided between each drive rim and the drum. The drive rim has a reduced diameter portion axially inwardly of the seal which receives a squeeze band acting to force the drive rim radially inwardly and the sealing surfaces of the groove and rib together.

United States Patent [72] Inventor Donald J. Bobo 8511 Roosevelt Way N.E., Seattle, Wash; 98115 [21] Appl. No. 813,060 [22] Filed Apr. 3, 1969 [45] Patented May 25, 1971 [54] ROCK-POLISHING RUMBLE 10 Claims, 4 Drawing Figs.

[52] US. Cl 51/164 [51] Int. Cl B24b 31/02 [50] Field of Search 51/164 [56] References Cited UNITED STATES PATENTS 3,134,203 5/1964 Roberts 51/164 2,210,584 8/1940 l-lileman 51/164 3,167,890 2/1965 Smith 51/164 Primary Examiner-Harold D. Whitehead AttarneyGraybeal, Cole & Barnard ABSTRACT: A molded tubular drum of elastomeric material having a generally cylindrical external shape and a polygonal internal shape. identical and closures for the drum, each also of molded elastomeric material and each having a radial end wall, an axially inwardly extending center plug shaped to snugly fit within the inner cavity of the drum, and aperipheral drive rim. A girth rib and girth groove seal is provided between each drive rim and the drum. The drive rim has a reduced diameter portion axially inwardly of the seal which receives a squeeze band acting to force the drive rim radially inwardly and the sealing surfaces of the groove and rib together.

PATENTEU mwzslsm 3579.921

INVENTO/F; M1. DONALD J B080 MWM KWQ ROCK-POLISHING RUMBLE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to the field or rock polishing, and more particularly to a new type of rumble or tumbler.

2. Description of the Prior Art Conventional rock polishing rumbles comprise a tubular metallic body, a removable rubber insert for the body, and removable sideplates or lids. Lid gaskets are bonded to the lids and wingnut and threaded stud assemblies are used for securing the lids to the drum.

One disadvantage of rumbles of this type is that they are relatively expensive to manufacture. The metallic parts must be manufactured aside from the rubber parts, the fastening studs must be secured to the metallic drum, and the lid gasket must be bonded to the lid. Also, use of the rumble requires the manipulation of a plurality of wingnuts.

A second major disadvantage of this type of rumble is that they are noisy in use. Proper polishing of rocks requires a continuous operation of the polishing machine for a period of several weeks. If the metallic drum alone were to be utilized, a considerable noise would be generated by the tumbling rocks as they fall against the lower portion of the drum body. This noise would be quite discomforting if it had to be heard for a prolonged length of time. It is for this reason that the conventional rumbles are lined with rubber; However, it has been found a rubber lining does not reduce the noise down to a level at which it is no longer disturbing. However, as they tumble the rocks still exert a force on the metal material, causing the metal to function like a sound board.

SUMMARY OF THE INVENTION In preferred form, the rumble of the present invention is characterized by a five-piece construction, all parts of which are cast or molded from rubber or a like resilient or elastomeric material having resilient or bounce characteristics like those found in rubber tires.

In the preferred form, the rumble comprises a tubular body or drum portion which is either cast by itself, or is cast end-toend with one or more other drum portions. The end assemblies are identical, and each comprises a one-piece lidlike casting including a radial end wall and a peripheral rim. A rib and groove seal is provided between each rim and each end of the drum. Each end assembly also includes a rubberband for applying a squeezing pressure on a reduced diameter lip portion of the peripheral rim at a location axially inwardly of the seal. The seal used to prevent leakage from within the drum comprises all molded parts. The radial end walls each include an inwardly projecting plug of an off-round configuration shaped to match the internal cross-sectional configuration of the drum. A circumferential groove is formed in each end wall radially between the plug and the peripheral rim. The fit of the end portion of the drum into such groove, the mating of the rib and the groove, and the inward squeeze applied by the rubberband, causing tighter engagement between the contacting surfaces, all contribute to provide the rumble with good sealing characteristics.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an end elevational view of a rock-polishing machine, showing a rumble of the invention positioned on the support and drive rollers of the tumbling mechanism;

FIG. 2 is a top plan view of the machine shown by FIG. 1, showing two rumbles in use end-to-end;

FIG. 3 is an exploded isometric view of the rumble; and

FIG. 4 is a fragmentary axial section view taken through an end portion of the rumble, substantially along line 44 of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIGS. 1 and 2 the rumbles R are shown to be positioned on a pair of laterally spaced, parallel tumbling rollers 10, 12. The rollers 10, 12 are supported at their ends by be'arings l4 which are carried by end members 16, 18 of the tumbling mechanisms housing. A pulley 20 is secured to one end of roller 10, outwardly of the wall 18. A drive belt 22 extends between pulley 20 and a second smaller pulley 24 connected to the output shaft of a drive motor M. The opposite end of roller 10 carries a pulley 26 and a second drive belt 28 drivenly connects the pulley 26 'with a similar pulley 30 carried by the adjacent end of roller 12. In operation, through the intermediacy of the pulleys 24, 22, 26, 30 and the drive belts 32, 28, the motor M rotates both rollers I0, 12 in the same direction, and the rollers 10, [2 apply a rotating force on the drive rim portions of the rumbles R.

Referring now to FIGS. 3 and 4, the rumble of the present invention is shown to comprise a tubular body or drum portion 32 and a pair of identical end closure assemblies 34. Preferably, all parts of body 32 and end assemblies 34 are constructed from a resilient rubberlike material which is comparable in resiliency or bounce to the rubber used in automobile tires.

Each end closure assembly 34 includes a removable cap 36 comprising a radial end wall 38 and a peripheral drive rim 40. The caps 36 are frictionally secured to the ends of the drum 32. Wall 38 is formed to include an inwardly projecting plug portion 42 having an off-round configuration, and shown in the drawing to be of hexagonal form. The inner cavity of drum 32 is of complementary shape (at least at the end portions thereof which receive the plugs 42), so that once a lid 36 is placed on the drum 32 it cannot be rotated relative to the drum. Thus, the rotational force applied to the drive rims 30 by the rollers 10, 12 is transmitted through the plugs 42 directly to the drum 32.

The drive rim is shown to include a girth groove 44 formed in the inner surface thereof substantially radially outwardly of the inner surface of plug 42. Groove 44 is positioned to receive a girth rib 46 formed on the radially outer surface of drum 32 near the end thereof. Rim 40 is shown to also include an axially inwardly projecting portion 48 of reduced diameter, adapted to receive a large rubberband 50 or some other bandtype member capable of imposing a radially inwardly directed force on the lip 48. Band 50 in effect squeezes" the lip 48 inwardly, causing good sealing contact to occur between the groove and rib 44, 46. The portion of rim 40 which extends axially outwardly of the band 50 is preferably larger in diameter than the band, so that it is this outer portion of the rim 40 which rests on and is driven by the rollers 10, 12, rather than the band.

Each of the five parts (drum 32, two lids 36 and two bands 50) which make up the rumble R are preferably cast from the rubber or other resilient material from which they are made. Owing to the shape of drum 32, plural drums 32 can be cast together end-for-end, and then sawn or otherwise cut apart. Or, if it is desirable to make one large drum of double capacity, two sections 32 can be left joined together, providing a single drum of double the usual length. I i

I claim:

I. A rumble comprising: a tubular drum having a hollow interior and opposite ends, and an end closure assembly at each end, each said closure assembly comprising a radial end wall and a peripheral rim which in use is frictionally driven by a rotating drive means in contact with said rims, with at least one of said end closure assemblies being removable from the tubular drum and serving as an operable closure therefor, such end closure, assembly including an axially inwardly projecting plug portion that is noncircular, with the interior end portion of the drum being of a complementary shape and receiving said plug, whereby during use of the rumble the driving force applied to the rim of such removable closure will be transmitted from such closure through the plug to the drum and the closure assembly cannot rotate relative to the drum, with a groove being defined in said removable closure radially between said plug and the drive rim, and with the end portion of the drum being frictionally received in said groove.

2. A rumble according to claim 1, wherein both ends of the drum are alike and each end closure is removable and is of the character described.

3. A rumble according to claim 1, wherein the end wall and drive rim portions of the removable closure assembly are of one piece construction and are cast from a resilient material, with a girth groove being formed in one of the radial inner surface of the drive rim and the radially outer surface of the drum, and with a receiving girth groove being formed in the other of said surfaces.

4. A rumble according to claim 3, wherein both ends of the drum are alike and each end closure is removable and is of the character described.

5. A rumble according to claim 3, wherein the rim of the removable end closure assembly has a reduced diameter portion, and said assembly further includes a band member locatable at said reduced diameter portion for establishing a radially inwardly directing force on the rim at such position.

6. A rumble according to claim 5, wherein both ends of the drum are alike and each end closure is removable and is of the character described.

7. A rumble according to claim 5, wherein said band is spaced axially inwardly of the drum from the mating rib and groove.

8 A rumble according to claim 7, wherein both ends of the drum are alike and each end closure is removable and both are of the character described.

9. A rumble according to claim 8, wherein said drum is constructed from a resilient material.

10. A rumble according to claim 9, wherein said off-round shape at the inner ends of the drum extend uniformly throughout the full length of the drum. 

1. A rumble comprising: a tubular drum having a hollow interior and opposite ends, and an end closure assembly at each end, each said closure assembly comprising a radial end wall and a peripheral rim which in use is frictionally driven by a rotating drive means in contact with said rims, with at least one of said end closure assemblies being removable from the tubular drum and serving as an operable closure therefor, such end closure, assembly including an axially inwardly projecting plug portion that is noncircular, with the interior end portion of the drum being of a complementary shape and receiving said plug, whereby during use of the rumble the driving force applied to the rim of such removable closure will be transmitted from such closure through the plug to the drum and the closure assembly cannot rotate relative to the drum, with a groove being defined in said removable closure radially between said plug and the drive rim, and with the end portion of the drum being frictionally received in said groove.
 2. A rumble according to claim 1, wherein both ends of the drum are alike and each end closure is removable and is of the character described.
 3. A rumble according to claim 1, wherein the end wall and drive rim portions of the removable closure assembly are of one piece construction and are cast from a resilient material, with a girth groove being formed in one of the radial inner surface of the drive rim and the radially outer surface of the drum, and with a receiving girth groove being formed in the other of said surfaces.
 4. A rumble according to claim 3, wherein both ends of the drum are alike and each end closure is removable and is of the character described.
 5. A rumble according to claim 3, wherein the rim of the removable end closure assembly has a reduced diameter portion, and said assembly further includes a band member locatable at said reduced diameter portion for establishing a radially inwardly directing force on the rim at such position.
 6. A rumble according to claim 5, wherein both ends of the drum are alike and each end closure is removable and is of the character described.
 7. A rumble according to claim 5, wherein said band is spaced axially inwardly of the drum from the mating rib and groove.
 8. A rumble according to claim 7, wherein both ends of the drum are alike and each end closure is removable and both are of the character described.
 9. A rumble according to claim 8, wherein said drum is constructed from a resilient material.
 10. A rumble according to claim 9, wherein said off-round shape at the inner ends of the drum extend uniformly throughout the full length of the drum. 